Update Statement

The UPDATE statement in SQL is used to modify the existing data of a table in database. We can update single columns as well as multiple columns and single record as well as multiple records using UPDATE statement as per our requirement.

Syntax:

UPDATE table_name

      SET column1 = value1, column2 = value2,...

WHERE condition;

table_name: name of the table

SET: Set statement is used to set new values to the particular column.

column1: name of first, second, third column....

value1: new value for first, second, third column....

WHERE: WHERE clause is used to select the rows for which the columns are needed to be updated. If we have not used the WHERE clause then the columns in all the rows will be updated.

condition: condition to select the rows for which the

values of columns need to be updated.

Example:

ID	NAME	ADDRESS	DEPARTMENT
101	Rajesh	Ghaziabad	IT
102	Swati	Delhi	Non IT
103	Manoj	Noida	IT
104	Sachin	Noida	IT

•          Update address to Delhi of ID 104:

SCRIPT:

    UPDATE EMPLOYEE

         SET ADDRESS = ‘Delhi’

    WHERE ID = 104;

Now EMPLOYEE table have following records:

ID	NAME	ADDRESS	DEPARTMENT
101	Rajesh	Ghaziabad	IT
102	Swati	Delhi	Non IT
103	Manoj	Noida	IT
104	Sachin	Delhi	IT

• Update all employee address to Delhi:

SCRIPT:

    UPDATE EMPLOYEE

         SET ADDRESS = ‘Delhi’;

Now EMPLOYEE table have following records:

ID	NAME	ADDRESS	DEPARTMENT
101	Rajesh	Delhi	IT
102	Swati	Delhi	Non IT
103	Manoj	Delhi	IT
104	Sachin	Delhi	IT

•          Update address to Delhi of ID 104 and also change Department to “Non IT”:

 SCRIPT:

   UPDATE EMPLOYEE

         SET ADDRESS = ‘Delhi’,

                DEPARTMENT = ‘Non IT’

   WHERE ID = 104;

Now EMPLOYEE table have following records:

ID	NAME	ADDRESS	DEPARTMENT
101	Rajesh	Ghaziabad	IT
102	Swati	Delhi	Non IT
103	Manoj	Noida	IT
104	Sachin	Delhi	Non IT